Charities with diversity at their heart will make better decisions, the former head of MI5 told an audience of charity finance professionals yesterday.

Baroness Eliza Manningham-Buller - – now chair of the Wellcome Trust – was delivering the opening keynote at the Charity Finance Summit, Civil Society Media’s annual conference.

She said that leadership didn’t have to be templated, and that leaders did not need successful role models to be successful themselves. She said that it was important that charity leadership and governance included diversity of thought, and said that MI5 had been improved when professionals from different organisations had been seconded, because they brought in different viewpoints and skills.

She also stressed that it was important to do things your own way – and that if you were a woman, you did not need to do things the same way as a man to be successful.

“As leaders of organisations you want diversity,” she told delegates. “Your competence as an organisation comes from having a diverse range of views. You have a much richer decision-making process.”

She said it had been useful that her predecessor and successor had been different from her.

“I made the mistake of thinking at the Wellcome Trust that I couldn’t do the top job because I wasn’t a male businessman,” she said. “I thought you needed to know the finance better. But I had different talents.

“Trying to have a role model who you model yourself on is disastrous. Women are always told we need role models. We don’t. That’s not to say that you can’t look at leaders and say ‘They did that well’ and copy that. But you should also think ‘They didn’t do that well and I’m not going to do it like that’.”

She also told delegates to be suspicious of the idea that because something had not worked, that meant someone had failed.

“The Daily Mail believes that if anything goes wrong there must have been failure,” she said. “But sometimes you do everything right and the correct answer is only clear with hindsight.”

She said that it was inevitable that everyone made mistakes.

“It’s become a myth that you can’t make mistakes,” she said. “We all make mistakes. What matters is how you handle it.”

She said that anyone in a leadership position should be suspicious of trying to know everything.

“Leadership needn’t be lonely,” she said. “It’s only lonely if you stick yourself on a pedestal and pretend you know all the answers. If you take yourself too seriously, you will find that your staff don’t take you seriously at all.

“As a leader the people who are most valuable are those who give you feedback.”